1. Field of the Invention
The invention relates to a method for processing plastic waste, especially polyolefins and a device for processing plastic waste, especially polyolefins used in particular in industrial utilization of plastic waste.
2. Brief Description of the Background of the Invention Including Prior Art
There is a known method of continuous plastic waste processing according to the Polish patent application P-358774 and a device for continuous processing of plastic waste. The processing method consists in that the plastic charge in a single-stage process is loaded, plasticized, fluidized and transformed thermocatalytically until a gas product is obtained, which is used for obtaining a hydrocarbons mixture constituting high-quality paraffin. The process is carried out in an inner vessel of an integrated vertically-oriented melting-exchange-reactor device where the plasticized and fluidized charge is converted into a uniform block of charge mass falling gravitationally. The device has a modular construction for single-stage process from the feeding point of charge to collecting a gas product and removing impurities.
According to the Polish patent application P-352341 there is another known method and production line for continuous processing of plastic waste where the waste is portioned and the charge is then delivered into a technological line, plasticized, forced into a reactor, where the plasticized charge is formed in the reactor into a uniform core falling gravitationally which is fluidized at the bottom and proportioned to the stabilizer. The final product is delivered into a cooler and liquefied.
From the publication of U.S. Pat. No. 5,500,120 titled “Auger-type chemical reformer” is known an apparatus for chemical reforming of organic materials which comprises a tubular housing having a longitudinal axis, and an open-end tube rotatably positioned in the tubular housing generally parallel to the axis, which tube carries radially extending projections.
Another publication of patent application no. US 2009/0321317 titled “Method and device for processing plastic-containing waste” teaches a method and device for processing plastic-containing and organic fluids based on crude oil, cooking oil, fats or the like. According to this publication the substance mixture is fed into a reactor, is then melted in the melting zone of the reactor and the interfering substances are discharged from the melt. The long-chained polymers still present in the melt are cracked in a crack zone of the reactor until they assume a gaseous state. Then the gas phase is discharged from the reactor an condensed in a cooler. Impurities are then removed from the volatile liquid present after cooling and the volatile liquid is stored.
Yet another publication of U.S. Pat. No. 4,235,676 titled “Apparatus for obtaining hydrocarbons from rubber tires and from industrial and residential waste” teaches that organic waste material such as industrial plastic waste is moved through the tube at a uniform rate of speed in the absence of air and/or oxygen, with the material being churned or tumbled as by means of a screw conveyor. The vapors and gases which are produced and/or liberated within the tube are quickly removed therefrom by means of a vacuum of from about four inches to about six inches of mercury, with the vapors being condensed and the gases separated therefrom.
In turn, the publication of international patent application no. WO 2008/081028 titled “Process and apparatus for waste treatment” teaches processes and apparatus for improving municipal waste treatment in autoclave processes. Improvements relate to the use of air-waste stream treatment, indirect heating with thermal fluid, forced steam transfer, autoclave design, waste treatment of contaminated air, classifiers for better separation of fibres from glass or grit and processing.
The publication of U.S. Pat. No. 5,190,226 titled “Apparatus and method for separation, recovery, and recycling municipal solid waste and the like” teaches introducing solid waste materials into a rotatable pressure vessel, rotating, pressurizing, and heating the pressure vessel and thus the waste material while simultaneously applying an extruding action to the solid waste material. The extruding action is achieved by a rotatable extruder mechanism carried in the pressure vessel which forces the processed solid waste material through a constricted area adjacent the exit of the pressure vessel.
Another publication of U.S. Pat. No. 5,427,650 titled “Apparatus and method for preparation for separation, recovery, and recycling of municipal solid waste and the like” teaches introducing solid waste materials into a rotatable pressure vessel, rotating, pressurizing, adding pH controlling chemicals and heating the pressure vessel and thus the waste material while simultaneously applying a mixing action to the solid waste material. The addition of a predetermined amount of pH controlling chemicals and the application of a vacuum serve to control the moisture content of the final fine organic portion of the processed material.
Furthermore, the publication of international patent application no. WO 02/26914 titled “Apparatus and method for recovering marketable products from scrap rubber” teaches feeding tire shreds to a pyrolysis vessel and pyrolyzing the shreds in a pyrolysis vessel to produce a pyrolysis gas and carbon black mixture. The pyrolysis gas processed by centrifugally separating entrained particles therefrom, separating the pyrolysis gas into a hydrocarbon condensate and a light vapor, removing entrained hydrocarbon condensate from the light vapor, and purifying and refining the hydrocarbon condensate. The carbon black mixture is processed by pulverizing the mixture to break up all strands and clumps of inorganic solids.
The known methods are usually based on gravitational falling of charge processed by thermal or catalytically-thermal cracking, so any disturbance of that falling has a direct influence on the entire process. Therefore there are problems with maintaining continuity of the process and its efficiency, which directly influences the economic aspect of the entire process.